Update EEqn.H & YEqn.H for dfLowMachFoam and dfSprayFoam

[xiao312]

No description provided.

[zhixchen]

There is still redundancy in the code. Please revise further.

[zhixchen]

There is still redundancy in the code. Please revise further.

For example:

fvScalarMatrix EEqn
(
fvm::ddt(rho, he) + mvConvection->fvmDiv(phi, he)
+ fvc::ddt(rho, K) + fvc::div(phi, K)
- dpdt
turbName == "laminar"
?
(
+ diffAlphaD
- fvc::div(hDiffCorrFlux)
)
==
fvm::laplacian(turbulence->alphaEff(), he)
);